Searching For Text In Files

find a text string in files.

grep -Rnw '/path/to/somewhere/' -e 'pattern'

-r or -R is recursive ; use -R to search entirely
-n is line number, and
-w stands for match the whole word.
-l (lower-case L) can be added to just give the file name of matching files.
-e is the pattern used during the search

--exclude, --include, --exclude-dir flags can be used for more acurate searching
This example will only search through those files which have .c or .h extensions:

grep --include=\*.{c,h} -rnw '/path/to/somewhere/' -e "pattern"

This will exclude searching all the files ending with .o extension:

grep --exclude=\*.o -rnw '/path/to/somewhere/' -e "pattern"

For directories, it's possible to exclude one or more directories using the --exclude-dir parameter. For example, this will exclude the dirs dir1/, dir2/ and all of them matching *.dst/

grep --exclude-dir={dir1,dir2,*.dst} -rnw '/path/to/search/' -e "pattern".